Miscanthus sinensis plant named ‘M77’

ABSTRACT

A new variety of  Miscanthus sinensis  plant named ‘M77’ produces a reduced number of seeds, making it less invasive.

Latin name of the genus and species of the plant claimed: ‘M77’ is avegetatively propagated ornamental perennial Miscanthus cultivar of thegenus and species Miscanthus sinensis.

Variety denomination: The new Miscanthus sinensis claimed is of thecultivar denominated ‘M77’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofMiscanthus sinensis herein referred to as ‘M77’.

The new Miscanthus sinensis is a product of a planned research,evaluation, and testing program conducted by the Inventors in Tifton,Ga. The objective of the Miscanthus sinensis research program is tocreate a new plant cultivar with reduced seed production. This cultivaris commercially important for its superior ornamental value and low seedproduction. These and other qualities are enumerated herein.

There is a need for a seed sterile Miscanthus cultivar becauseMiscanthus cultivars produce higher seed set at higher elevations whichtend to make this genus invasive. Unprotected roots of respective groupsof 59, 44, and 49 Miscanthus sinensis ‘Gracillimus’ plants wereirradiated with 4-, 8-, and 12-Kr, respectively, of Cobalt 60 radiationand transplanted to a test field at Tifton, Ga. on Apr. 21, 2006. OnAug. 9, 2006, 37 and 1 plants were observed to have survived the 4-Krtreatment, and one plant was observed to have survived the 8-Krtreatment. Seven plants from the 4-Kr treated plants had tillers withreduced seed set. One plant, designated 4-22-1-1, had tillers with noseed set. A culm from 4-22-1-1 was designated M8-4 in 2008 and observedfor seed set thru 2009 at Tifton, Ga. (elevation about 350 ft.). In2010, M8-4 was designated as M8 and planted at Blairsville, Ga.(elevation about 1,880 ft.) in 2010. In 2010, M8 produced one seed perinflorescence at Tifton, Ga. and no seed at Blairsville, Ga. while theMiscanthus sinensis ‘Gracillimus’ control plants produced numerous seedsper inflorescence at both locations in non-replicated tests. The seedsterile plant observed at Blairsville, Ga. (high elevation) wasdesignated ‘M77’. This ‘M77’ plant was then asexually propagated byvegetative propagation. The resulting ‘M77’ plants were tested atTifton, Ga. and Blairsville, Ga. in replicated tests from 2012 thru2015. Tests consisted of five and three single plant replicationsarranged in a randomized complete block experiment at Tifton, Ga. andBlairsville, Ga., respectively.

Asexual reproduction of the new Miscanthus ‘M77’ by vegetativepropagation (single stem propagules) in a controlled environment inTifton, Ga. and Blairsville, Ga. since 2012, has shown that the uniquefeatures of this new Miscanthus sinensis cultivar are stable andreproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent thecharacteristics of a new M. sinensis cultivar ‘M77’. The new cultivar‘M77’ has not been observed under all possible environmental conditions.The phenotype may vary somewhat with variations in, for example,temperature, day-length, light intensity, soil types, and water andfertility levels without, however, any variance in genotype.

Throughout this specification, color names beginning with a small lettersignify that the name of that color, as used in common speech, is aptlydescriptive. Color names beginning with a capital letter designatevalues based upon The R.H.S. Colour Chart, 5^(th) edition published byThe Royal Horticultural Society, London, England.

The following traits have been repeatedly observed for the new M.sinensis cultivar ‘M77’ in Tifton, Ga. and Blairsville, Ga. and can becompared to M. sinensis ‘Gracillimus’:

-   -   1. ‘M77’ plants produce few seeds, especially at high        elevations.    -   2. ‘M77’ plants exhibit a vigorous growth habit.    -   3. ‘M77’ plants are highly seed sterile.

The new cultivar Miscanthus ‘M77’ can be compared to its parent,Miscanthus sinensis var. Gracillimus.

Plants of the new Miscanthus ‘M77’ differ from its parent ‘Gracillimus’,at least in the following characteristic:

The new cultivar ‘M77’ produces significantly fewer seeds compared to‘Gracillimus’, the closest known variety. In addition, the few seedsthat ‘M77’ produces also have been observed to have significantly lessgermination potential than seeds of ‘Gracillimus’. In one observation:(1) seeds from ‘M77’ plants growing at Tifton, Ga. did not germinate;while ‘Gracillimus’ seeds germinated at a 42% rate (LSD−5%=17); and (2)seeds from ‘M77’ plants growing at Blairsville, Ga. germinated at a 32%rate; while ‘Gracillimus’ seeds germinated at a 70% (LSD−5%=15).Inflorescences from numerous plants of ‘M77’ had to be searched in orderto obtain enough ‘M77’ seeds for germination. Also, on average theheight of ‘M77’ inflorescences are less than the height of ‘Gracillimus’inflorescences.

The following observations, measurements, and values describe plantsgrown in Tifton, Ga. and Blairsville, Ga. In Tables 1-7, the leastsignificant difference (LSD) is set at P≤0.05 probability level. Growthdays were included in ratings. Plants were spaced 2 meters center tocenter spacing. Plants were established as single stem propagules inmid-April to mid-May and rated in September through October. Data wastaken from plants during year of establishment in 2012 at Tifton, Ga.and 2013 in Blairsville, Ga. Data were also taken in 2013 and 2014 fromover-wintered 2012 and 2013 plants at Tifton, Ga. and in 2013 and 2015from over-wintered 2012 plants at Blairsville, Ga.

Inflorescence height of the new cultivar ‘M77’ was significantly shorterthan those of ‘Gracillimus’ in four of seven tests (Table 1). Height ofthe leaf canopy of ‘M77’ was significantly shorter than that of‘Gracillimus’ in three of seven tests (Table 2). Canopy diameter wassignificantly narrower for ‘M77’ compared to ‘Gracillimus’ in only twoof seven tests (Table 3). This appeared to be related to the year ofestablishment. There appeared to be only small differences in canopydiameter between ‘M77’ and ‘Gracillimus’ after the year ofestablishment. As expected, plants tended to become more robust as theybecome older. Differences in inflorescence length appeared to be smallbetween the ‘M77’ and ‘Gracillimus’ and significant only in two of threeyears at Tifton, Ga. (Table 4). ‘M77’ usually had fewer inflorescencesthan ‘Gracillimus’, but this trait was significant in only three ofseven tests (Table 5). Inflorescence number appeared to vary greatlyfrom plant to plant (probably environmental effects). Leaf length andwidth were similar for ‘M77’ and ‘Gracillimus’ (Table 6). However,leaves of ‘Gracillimus’ were significantly longer than those of ‘M77’ atTifton in 2013. The data shows (Table 7) that seed set was greatlyreduced for ‘M77’ compared to ‘Gracillimus’ and statisticallysignificant for all years tested.

Although ‘M77’ sets a small amount of seed, we wanted to know how manyof the seed produced actually germinated. In 2015, we tested thegermination of 2014 harvested seed from ‘M77’ plants from both Tifton,Ga. and Blairsville, Ga. Note: a very large number of inflorescences of‘M77’ needed to be harvested at Tifton, Ga. and Blairsville, Ga. inorder to get enough seed to germinate of this cultivar. None of the seedfrom the Tifton, Ga. harvest germinated while only 32% of the seedharvested at Blairsville, Ga. germinated (Table 7), furtherdemonstrating high seed sterility. This characteristic reduces theinvasive potential of ‘M77’, which is especially needed at higherelevations. Seeds were stored in small kraft envelops in the threshingshed for six months. Seeds were then planted in steam-sterilized soiland allowed to germinate for 45 days. During the germination period theseeds went through random wet and dry periods. Seedling emergence wasrated at three dates during this period. In 2015, we also tested 75 and12 clones of ‘M77’ at Tifton, Ga. and Blairsville, Ga., respectively,for morphological uniformity and seed set. All were seed sterile andmorphologically uniform.

TABLE 1 Height of inflorescence of two Miscanthus sinensis ornamentalgrasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations inGeorgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/ 2012/ Entry2012 2013 2014 2014 2013 2013 2015 Growth 180 182 197 197 154 116 162Days ‘M77’ 122 111 133 203 200 122 184 ‘M90’ 145 143 136 208 212 144 210LSD 11 10 NS NS 12 11 NSIn Table 1, plant height measured from ground level to top ofinflorescence. All heights measured are in cm. At Tifton, Ga., ‘M77’ and‘Gracillimus’ were planted 18 Apr. 2012 and 13 Apr. 2013 andmeasurements were taken 15 Oct. 2012, 30 Sep. 2013, and 9 Sep. 2014,respectively. At Blairsville, Ga., ‘M77’ and ‘Gracillimus’ were planted14 Apr. 2012, and 16 May 2013, and measurements taken 9 Sep. 2013 and 24Sep. 2015, respectively. Single year is year planted and year datarecorded; double years are “year planted/year data recorded”.

TABLE 2 Height of leaves of two Miscanthus sinensis ornamental grasses(‘M77’ = experimental and ‘M90’ = var. ‘Gracillimus’) grown at twolocations in Georgia. Tifton, GA Blairsville, GA Entry 2012 2012/20132013/2014 2012/2014 2012/2013 2013 2012/2015 Growth 180 182 197 197 154116 162 Days ‘M77’ 66 67 106 136 122 66 151 ‘M90’ 90 76 100 140 144 89140 LSD 11 NS NS NS 11 10 NSIn Table 2, height of leaves were measured from ground level to top ofleaf canopy. All height measurements are in cm. At Tifton, Ga., testswere planted 18 Apr. 2012 and 13 Apr. 2013 and measurements were taken15 Oct. 2012, 30 Sep. 2013, and 9 Sep. 2014. At Blairsville, Ga., testswere planted 14 Apr. 2012, and 16 May 2013, and measurements were taken9 Sep. 2013 and 24 Sep. 2015. Single year designation is year plantedand year data recorded; double years designations are “year planted/yeardata recorded”.

TABLE 3 Canopy diameter of two Miscanthus sinensis ornamental grasses(‘M77’ = experimental and ‘M90’ = var. ‘Gracillimus’) grown at twolocations in Georgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/2013 2014 2014 2013 2014 2015 ‘M 77’ 58 91 151 100 54 184 ‘M 90’ 66 88153 135 128 159 LSD NS NS NS 25 20 NS GD 182 197 197 116 130 162Canopy diameter measurements are the average diameter of the widest andthe narrowest diameter of a single plant canopy. All canopy measurementsare in cm. At Tifton, Ga., tests planted were 18 Apr. 2012 and 13 Apr.2013 and measurements were taken 30 Sep. 2013, and 9 Sep. 2014. AtBlairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and15 May 2014 and measurements taken 9 Sep. 2013, 22 Sep. 2014 and 24 Sep.2015. Single year designation is year planted and year data recorded;double years designations are “year planted/year data recorded”.

TABLE 4 Inflorescence lengths of two Miscanthus sinensis ornamentalgrasses ‘(M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations inGeorgia. Tifton Blairsville 2012 2012/2013 2013 2012/2013 2012/2015Growth 180 182 116 154 162 Days ‘M77’ 20 36 20 33 28 ‘M90’ 26 35 25 3229 LSD 2 NS 2 NS NSAt Tifton, Ga., tests were planted 18 Apr. 2012 and 13 Apr. 2013 andmeasurements were taken 15 Oct. 2012, and 30 Sep. 2013. At Blairsville,Ga., tests were planted 14 Apr. 2012, and 16 May 2013, and measurementswere taken 9 Sep. 2013 and 24 Sep. 2015. All canopy measurements are incm. Single year designation is year planted and year data recorded;double years designations are “year planted/year data recorded”.

TABLE 5 Number of inflorescences of two Miscanthus sinensis ornamentalgrasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations inGeorgia. Tifton, GA Blairsville, GA 2012/ 2013/ 2012/ 2012/ 2012/ 20122013 2014 2014 2013 2013 2015 GD 180 182 197 197 154 116 162 ‘M77’ 23 20103 86 81 21 133 ‘M90’ 34 57 95 127 108 83 153 LSD 17 NS NS 23 NS 37 NS

At Tifton, Ga., tests were planted 18 Apr. 2012 and 13 Apr. 2013 andmeasurements taken 15 Oct. 2012, 30 Sep. 2013, and 9 Sep. 2014. AtBlairsville, Ga., tests were planted 14 Apr. 2012, and 16 May 2013, andmeasurements were taken 9 Sep. 2013 and 24 Sep. 2015. Single yeardesignation is year planted and year data recorded; double yearsdesignations are “year planted/year data recorded”.

TABLE 6 Leaf length and width of two Miscanthus sinensis ornamentalgrasses (‘M77’ and ‘M90’ = var. ‘Gracillimus’) grown at two locations inGeorgia. Tifton, GA Blairsville, GA Tifton, GA Blairsville, GA LengthLength Width Width 2012/2013 2012/2015 2012/2013 2012/2015 Growth 182162 182 162 Days ‘M 77’ 44 68 4.37 5.2 ‘M 90’ 53 52 4.57 5.5 LSD 6 NS NSNS

At Tifton, Ga., test was planted 18 Apr. 2012 and measurements weretaken 30 Sep. 2013. Leaf length (average from 3 culms) was measured fromthe leaf collar to the leaf tip of the latest fully extended leaf. AtBlairsville, Ga., test was planted 14 Apr. 2012 and measurements weretaken 24 Sep. 2015. Leaf width (average from 3 culms) was measured inthe center of the latest fully extended leaf. Leaf length measurementsare in cm. Leaf width measurements are in mm. Double year designationsindicate “year planted/year data recorded”.

TABLE 7 Seed set of two Miscanthus sinensis ornamental grasses (‘M77’and ‘M90’ = var. ‘Gracillimus’) grown at two locations in Georgia. Seedsper Inflorescence Tifton, GA Blairsville, GA Seed Germination - % 2012/2012/ 2012/ 2012/ 2012/ Tifton Blairsville Entry 2013 2014 2015 20132014 2015 2014 2014 ‘M77’ 0.0 7 0 0.02 0.4 0 0 32 ‘M90’ 0.02 256 588 2451 138 42 70 LSD 0.0 2 129 0.0 0.0 0.0 17 15

At Tifton, Ga., tests were planted 18 Apr. 2012 and 12 May 2015 andseeds were harvested in Oct. of 2013, 2014 and 2015. At Blairsville,Ga., test was planted 14 Apr. 2012, and seeds were harvested in Oct.2013. 2014 and 2015. Number of seeds per inflorescence was determinedfrom the mean of four random inflorescences from each replication. Seedgermination tests was conducted on 25 seeds from four and threedifferent plants (replicatons) harvested in Oct. 2014 at Tifton andBlairsville, Ga. Germination tests were conducted in April of 2015 toallow seeds to go through a dormancy period and simulate fieldconditions. Double year designations indicate “year planted/year datarecorded”.

TABLE 8 Summary of morphological characteristics of two Miscanthussinensis cultivars. Trait ‘Gracillimus’ ‘M77” Mature inflorescence136-210 cm 111-203 cm height Mature leaf height 76-144 cm 66-151 cmDiameter of plant canopy 66-159 cm 54-184 cm Inflorescence length 25-35cm 20-36 cm Number of Inflorescences 34-153 23-133 per plant Leaf width4.6-5.5 mm 4.4-5.2 mm Leaf length 52-53 cm 44-68 cm Adaxial leaf surfaceGlaborous Glabrous trichomes Abaxial leaf surface 4-6 mm long Sparse,less than trichomes 0.5 mm long Leaf blade margin Abundant, less thanAbundant, less than trichome length 0.5 mm long 0.5 mm long Leaf collartrichomes Dense, 4-6 mm long Dense, 3-5 mm long Sheath trichomes Lessthan 0.5 mm long Scattered, less than 1 mm long Ligule Yes. 1-2 mm Yes,1-2 mm Ligule trichomes Dense, 3-4 mm long Dense, 3-4 mm long Sheathtrichomes Less than 0.5 mm long Abundant, less than 1 mm long Adaxialleaf color 143A 143A Abaxial leaf color 143A 143A Midrib color NN155DNN155D

In summary, ‘M77’ is similar to ‘Gracillimus’ in height, canopy width,inflorescence length, and leaf characteristics. ‘M77’ producesignificantly fewer seeds than ‘Gracillimus’ which should greatly reducethe invasiveness of this species.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying colored photographs illustrate the overall appearanceand distinct characteristics of the new cultivar of Miscanthus ‘M77’.The colors in the photographs are as close as possible with thephotographic and printing technology utilized.

Certain characteristics of this variety, such as growth and color, maychange with changing environmental conditions (e.g., light, temperature,moisture, nutrient availability, or other factors). Color descriptionsand other terminology are used in accordance with their ordinarydictionary descriptions, unless the context clearly indicates otherwise.Color designations are made with reference to The Royal HorticulturalSociety (R.H.S.) Colour Chart (5^(th) edition, 2007).

FIG. 1 is a photograph of the vegetative stage of the new cultivarMiscanthus ‘M77’.

FIG. 2 is a photograph of the flowering stage of the new cultivarMiscanthus ‘M77’.

The new cultivar ‘M77’ is a vigorous perennial at Blairsville, Ga. (USDAZone 7a). The new cultivar ‘M77’ (i) survived temperatures below 0° C.for 90 days, and a lowest temperature of −9° C., in Blairsville, Ga.during the winter of 2012/2013; (ii) survived temperatures below 0° C.for 95 days, and a lowest temperature of −29° C., in Blairsville, Ga.,during the winter of 2013/2014; and (iii) survived temperatures below 0°C. for 101 days, and a lowest temperature of −17° C., in Blairsville,Ga. during the winter of 2014/2015.

All data are from plants established as single stem propagules inmid-April to mid-May and rated in September through October, except thedouble year dates in the previous tables indicate “year ofestablishment/year data was collected”.

-   Plant:    -   -   Mature inflorescence height.—111-203 cm.        -   Mature leaf height.—66-151 cm.        -   Diameter of plant canopy.—54-184 cm.        -   Inflorescence length.—20-36 cm.        -   Number of inflorescences per plant.—23-133.-   Leaf:    -   -   Leaf width.—4.4-5.2 mm.        -   Leaf length.—44-68 cm.        -   Adaxial leaf surface trichomes.—Glabrous.        -   Abaxial leaf surface trichomes.—Sparse, less than 0.5 mm            long.        -   Leaf blade margin trichome length.—Abundant, less than 0.5            mm long.        -   Leaf collar trichomes.—Dense, 3-5 mm long.        -   Sheath trichomes.—Scattered, less than 1 mm long.        -   Ligule.—Yes, 1-2 mm.        -   Ligule trichomes.—Dense, 3-4 mm long.        -   Sheath trichomes.—Abundant, less than 1 mm long.        -   Adaxial leaf color.—143A.        -   Abaxial leaf color.—143A.        -   Midrib color.—NN155D.

What is claimed is:
 1. A new and distinct cultivar of the Miscanthusplant named ‘M77’, as illustrated and described.